/11. today. our focus what should have been a moment of joy turned to a time of carnage. president obama says justice will be done. > make no mistake, we will get to the bottom of this and we and find out who did this we will find out why they did this. >> the devices exploded near line a favorite spot for spectators. manythan 140 were injured, in a criminal conditio-- critic condition. people started throwing down the barricade and running over each other. ran the other direction. >> the f.b.i. has taken control investigation. the big question, was it international or domestic terror? aaron is here with business and talking music. >> it is all about how do you get your music and the answer is streaming, the ioneer in this is going global in the online world trying to cash in on this music revolution. > it is midday in london and 7:00 in b boston. a city is dealing with the bomben onof the worst u.s. soil since 9/11. three were killed and 140 competitors d injured. president obama has said those responsible for the acts will weight of justice. let's go over to boston now and bbc's reporter.